Strengthening flexible metallic pipes.



G. RUDOLPH. STRENGTHENING FLEXIBLE METALLIC PIPES.

' APPLIOATION FILED FEB. 27, 1909.

Patented Aug. 15, 1911.

VA VI VA "VA Swim 1m Z gibo vwma,

wit'weooao T all whom it may concern.

' CHARLES "RUD LPH, 0F PARIS,- FRANGE,1ASSIGNOR To cH si. r. sorronri,.or f

PHILAD LP IA, PENNSY ANIA;

s'rRnNe-Trmmne FLEXIBLE METALLIC r rrris'.

Patented Aug; 1

I Application filed February 27, 1909. Serial No. 480,363.

Be it known that I, CHARLES RUDoLPH, a

citizen of the-Republic of France, and a resident of 66 Rue du Theatre,Paris, France, have inventedcertain new and-useful Improvements forStrengthening Flexible-Me tallic Pipes, of which the following is afull, clear, and exact description, such as will enable others skilledin the art to which it appertains to carry out the same. This inventionrelates to flexible metallic ,pipes and has forits object an arrangement.'for strengthening and consolidating flexible metallic pipes of thatkind which are formed. by a metal band suitably shaped for the purpose,being wound in a helix.

When

' 7 these pipes are-subjected to moreor less prolonged tension, theedges'which are engaged one in the other are strained and thepipedeteriorated. In order toobviate this cause of deterioration, theinyention consists in providingthe pipe internally with a helicallywounds ring, the two ends of which are fixed to-t epipe' Whenthepipeexperiences a pull tending toelongate it, a portion of the tension istaken up by the internal spring, thus diminishing by this amount thestrain on the interlocking edges.

' the accompanying drawings :F igure lshows partly in section and partlyin elevation a means for carrying out this inven- 'tion; and Fig. 2shows a modification.

In thesefigures the shaped strip which is wound in a helix to formthepipe is indicated by 1, and 5? indicates the elastic packing-"forinsuring the tightness of the pipe.

I At the inside of the pipe at each end there is a ring 3, the edge ofwhich is bent back at 4: so as to give it a bearing on the pipe.

In the interior-of the pipe there is a helicoidal spring 5 of roundsection as shown in Fig. 1, or of-rectangular section as shown in Fig.2, the ends of which spring are fixed at 6 toeach of the rings 3, bysoldering or any other suitable means. It is evident that with thisarrangement, if a pull be ,ex-

' erted on 'a pipe of comparatively small length, a portion of thetension will be taken up by the spring, which will diminish by so 1 muchthe strain on the pipe. Although-the 5(.

rings 3 constitute the arrangement which' has been considered to bepreferable for attaching the extremities of the spring to the twoends ofthe pipe. This arrangement will find a special application in the con--=plings of the flexible pipes between railway carriages for pneumaticbrakes, and for heating purposes. These flexible pipes have to supportthe weight of the coupling pieces" intended for connecting them, andthis 60 weight exerts a strain on the pipes, which after a time resultsin strain of the pipes and wear of the. interengaged edges of thehelically wound band, which constitutes the p p With the arrangementaccording tothis invention, the spring takes up a portion of the pullexerted by the weight of the cou pling pieces and thus diminishesthestrain onthepipe.- I

This application is given merely as an'example and it does not limit theuses to which the invention may be applied.

I am aware that helicoidal springs in the interior of flexible pipeshave alreadybeen feature of mymvention is to fix the helical spring atboth extremities of the pipe formed by a shaped metal band wound in ahelix, with the object of taking up a portion ofthe tension exerted inthe direction of p the axis of the pipe.

Having now particularly described and ascertained the nature of my saidinvention and in what manner the samev is to be performed, I declarethat what I claim is:

A flexible metallic pipe comprising a helical'shaped metallic striparranged with the edges of, successive coils interlocking, in

com bina tion with collars "3 fitting wifihin In testim'ony I havehereunto set my hand said metallic strip and having outwardly in the,presence of the two-subscribing Witturned. flanges 4L abutting upon theends of nesses.

v saidvstrip, and a'helical spring Withinsaid CHARLES RUDOLPH.

pipe, lying against its inner surface and' Vi'tnesses: Y 'secured at itsends to said collare, 3, gub- F RANQDIVS DU BOISROUDRAY,

v'stantiallv as cleseribed: 7 H. C. 00x11.

